Inbreeding — mating restricted to a subset of a population sharing common ancestry — reduces effective gene pool size and raises the probability that two carriers of the same recessive allele will mate, thereby increasing the incidence of homozygous affected individuals for autosomal recessive disorders. The effect is asymmetric across inheritance modes: autosomal dominant disorders manifest in heterozygotes regardless of mate genotype, so mate-choice restriction does not materially change their transmission risk, whereas recessive carriers are phenotypically silent and their risk is entirely a function of carrier-frequency in the mating pool. This concept sits in population genetics and medical genetics, connecting allele-frequency dynamics and genetic diversity to Mendelian inheritance patterns and to the rationale for genetic counseling.
Inbreeding — mating restricted to a subset of a population sharing common ancestry — reduces effective gene pool size and raises the probability that two carriers of the same recessive allele will ma…